Thermosetting resins and photocurable resins are used as coating materials, paint materials, optical materials and adhesive materials. Curable compositions exhibiting a high curing rate that contain an acrylic acid ester or methacrylic acid ester as a principal component are widely used as thermosetting resins from the viewpoint that the operation efficiency and productivity can be enhanced. In particular, a bifunctional or higher-functional acrylic acid ester or methacrylic acid ester is employed for increasing the polymerization degree of cured resin to thereby increase the hardness of the surface of the cured resin.
However, in the curing of such a polyfunctional acrylic acid ester by radical polymerization, the polymerization is inhibited by oxygen to thereby produce uncured portion with the result that the problem of remaining tack is caused. Moreover, many of the acrylic acid esters exhibit high skin stimulation, so that, also, the problem of toxicity is encountered.
Vinyl ether compounds are known as being a photocurable compound whose skin stimulation is low. The vinyl ether compounds are cured by cationic polymerization, so that they are less susceptible to the polymerization inhibition by oxygen. However, the catalysts for use in the cationic polymerization have such drawbacks that they are deactivated by moisture or bases, they are expensive and the number of varieties thereof is small to thereby limit the number of really available catalysts and many thereof are highly toxic. Further, the radical polymerization of only one kind (single) vinyl ether does not proceed, so that, for example, the method of copolymerizing a vinyl ether and an acrylic material (monomer) is employed for effecting the radical polymerization. However, in this copolymerization, the copolymerizability cannot always be stated as being excellent and, even if the copolymerization by radical polymerization is performed, the production of product with satisfactorily high practicability is limited.
Recently, the use of a propenyl ether as a cationic polymerization material is drawing attention. Crivello et al. reported in J. Macromol. Sci. Part A, A31(9), 1105 (1994) that propenyl ethers exhibited high cationic polymerizability. The propenyl ether compounds have skeletal structures derived from phenols such as bisphenol.
Further, U.S. Pat. No. 4,864,054 reported that an aromatic propenyl ether compound could be used in various applications through the cationic polymerization thereof. This aromatic propenyl ether compound is one having a skeletal structure derived from a phenol such as bisphenol A or hydroquinone or from an ester such as a terephthalic acid ester or an isophthalic acid ester.
However, when the radical polymerization is intended, the problem is encountered such that the radical polymerizability of this propenyl ether alone is as low as that of the above vinyl ether.
The radical polymerization method has advantages in that, as compared with other polymerization methods, the curing time is generally relatively short, the molecular weight can be large, a large variety of radical polymerization initiators are available and their use is easy. Therefore, the radical polymerization method is an industrially useful polymerization method. However, a compound having a propenyl ether group or an allyl ether group whose sole radical polymerization is practicable is little known.
(1) Canadian Patent Specification No. 575985 describes esters prepared from a saturated or an unsaturated polycarboxylic acid and a .beta.-(2-propenoxy)alkanol of the formula RCH.dbd.CH--CH.sub.2 --O--CH(R')CH(R")--OH or CH.sub.2.dbd.C(R)--CH.sub.2 --O--CH(R')CH(R")--OH (wherein each of R, R' and R" is selected from among hydrogen and alkyls, the alkyls preferably being those which do not contain more than three carbon atoms, for example, methyl, ethyl or propyl).
Specifically, the specification discloses, as preferred esters, di-(.beta.-propenoxyethyl) maleate, di(.beta.-propenoxyethyl) fumarate (CH.sub.2.dbd.CH--CH.sub.2 --O--(CH.sub.2).sub.2 --OCO--CH.dbd.CH--COO--(CH.sub.2).sub.2 --O--CH.sub.2 --CH.dbd.CH.sub.2) and di-(.beta.-propenoxyethyl) itaconate (CH.sub.2.dbd.CH--CH.sub.2 --O--(CH.sub.2).sub.2 --OCO--CH(.dbd.CH.sub.2)CH.sub.2 --COO--(CH.sub.2).sub.2 --O--CH.sub.2 --CH.dbd.CH.sub.2). Further, the specification teaches that the copolymerization reaction of the above monomers is accelerated by the presence of a peroxide such as dibenzoyl peroxide or diacetyl peroxide.
However, the specification fails to present any specific description as to esters including an alkylene group having at least 3 carbon atoms or a cycloalkylene group having at least 5 carbon atoms in the moiety "CH(R')--CH(R")--" of the above formula.
(2) Japanese Patent Publication No. 55(1980)39533 discloses a process for producing an .omega.-vinyloxyalkyl carboxylate in which an unsaturated carboxylic acid and an .omega.-halogenoalkyl vinyl ether are condensed with each other.
(3) Further, Japanese Patent Laid-open Publication No. 57(1982)-165409 discloses a thermosetting composition containing a thermosetting catalyst, which comprises:
(A) an aromatic polyvinyl ether compound selected from among (i) polyvinyl compounds of the formula R[QR.sup.1 OC(R.sup.2).dbd.C(R.sup.3).sub.2 ].sub.n (wherein Q: --O--, --COO--, etc., R: polyvalent aromatic organic group, R.sup.1 : alkylene group having 1 to 8 carbon atoms, each of R.sup.2 and R.sup.3 : H or alkyl group having 1 to 8 carbon atoms, and n: 2 to 10) and (ii) reaction product of the above polyvinyl compound with an active hydrogen compound selected from a specified group including polycarboxylic acids, phenols, etc., and PA1 (B) (a) an aryl onium salt selected from a specified group and (b) an organic oxidant or an aromatic polyvinyl ether soluble copper compound. PA1 (a) reacting a polyol with a polybasic acid ester having vinyl ether terminals in the presence of a transesterification catalyst to thereby produce an oligomer of the polyol and the polybasic acid ester which has vinyl ether terminals and a by-product of hydroxymonovinyl ether, and PA1 (b) separating the hydroxymonovinyl ether during the reaction of the step (a). PA1 (wherein each of R' and R": H or lower alkyl group having 1 to 10 carbon atoms and Z: alkylene group or cycloalkylene group) and the chain extension reaction between vinyl ether terminated ester (iii) and polyol (HO-A-OH) are described as examples of the vinyl ether terminal forming reactions of ester. PA1 wherein X represents --CH.dbd.CH-- or --CH.sub.2 --C(.dbd.CH.sub.2)--, PA1 each of R.sup.1 and R.sup.2 represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5. PA1 an ester represented by the formula R.sup.3 --OCO--X--COO--R.sup.4 (wherein X represents --CH.dbd.CH-- or --CH.sub.2 --C(.dbd.CH.sub.2)-- and each of R.sup.3 and R.sup.4 independently represents an alkenyl group or alkyl group having 1 to 3 carbon atoms) and PA1 an alcohol represented by the formula CH.sub.3 --CH.dbd.CH--(OR.sup.5).sub.n --OH (wherein R.sup.5 represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5) PA1 to a transesterification reaction conducted in the presence of a transesterification catalyst to thereby obtain the above propenyl ether compound. PA1 wherein X represents --CH.dbd.CH-- or --CH.sub.2 --C(.dbd.CH.sub.2)--, each of R.sup.6 and R.sup.7 independently represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5, PA1 to thereby obtain the above propenyl ether compound. PA1 (i) at least one carboxylic acid or anhydride thereof selected from the group consisting of maleic anhydride, maleic acid, fumaric acid, itaconic acid and itaconic anhydride, and PA1 (ii) an alcohol represented by the formula CH.sub.2.dbd.CH--CH.sub.2 --(OR.sup.8).sub.n --OH (wherein R.sup.8 represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5) PA1 an ester represented by the formula R.sup.3 --OCO--X--COO--R.sup.4 (wherein X represents --CH.dbd.CH--or --CH.sub.2 --C(.dbd.CH.sub.2)-- and each of R.sup.3 and R.sup.4 represents an alkenyl group or alkyl group having 1 to 3 carbon atoms) and PA1 an alcohol represented by the formula CH.sub.2.dbd.CH--CH.sub.2 --(OR.sup.8).sub.n --OH (wherein R.sup.8 represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5) PA1 to a transesterification reaction conducted in the presence of a transesterification catalyst to thereby obtain the allyl ether compound of the above formula (2), and PA1 isomerizing the allyl ether compound to thereby obtain the above propenyl ether compound. PA1 (i) at least one unsaturated dicarboxylic acid or anhydride thereof selected from the group consisting of maleic anhydride, maleic acid, fumaric acid, itaconic acid and itaconic anhydride, and PA1 (ii) an alcohol represented by the formula CH.sub.2.dbd.CH--CH.sub.2 --(OR.sup.8).sub.n --OH (wherein R.sup.8 represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5, provided that, when n=1, it is preferred that R.sup.8 represent an alkylene group having 3 or 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms) to an esterification reaction conducted in the presence of an esterification catalyst, PA1 an ester represented by the formula R.sup.3 --OCO--X--COO--R.sup.4 (wherein X represents --CH.dbd.CH-- or --CH.sub.2 --C(.dbd.CH.sub.2)-- and each of R.sup.3 and R.sup.4 independently represents an alkenyl group or alkyl group having 1 to 3 carbon atoms) and PA1 an alcohol represented by the formula CH.sub.2.dbd.CH--CH.sub.2 --(OR.sup.8).sub.n --OH (wherein R.sup.8 represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5, provided that, when n=1, it is preferred that R.sup.8 represents an alkylene group having 3 or 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms) PA1 to a transesterification reaction conducted in the presence of a transesterification catalyst to thereby obtain the above allyl ether compound for use in radical polymerization. PA1 wherein X represents --CH.dbd.CH-- or --CH.sub.2 --C(.dbd.CH.sub.2)--, PA1 each of R.sup.1 and R.sup.2 represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5. PA1 wherein X represents --CH.dbd.CH-- or --CH.sub.2 --C(.dbd.CH.sub.2)-- and each of R.sup.3 and R.sup.4 independently represents an alkenyl group or alkyl group having 1 to 3 carbon atoms, and EQU CH.sub.3 --CH.dbd.CH--(OR.sup.5).sub.n --OH (4-b) PA1 wherein R.sup.5, like R.sup.1 or R.sup.2 of the formula (1), represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n, like n of the formula (1), is an integer of 1 to 5. PA1 lower alkyl esters of maleic acid, such as dimethyl maleate, diethyl maleate, dipropyl maleate and diisopropyl maleate; PA1 lower alkenyl esters of maleic acid, such as diallyl maleate; PA1 lower alkyl esters of fumaric acid, such as dimethyl fumarate, diethyl fumarate, dipropyl fumarate and diisopropyl fumarate; PA1 lower alkenyl esters of fumaric acid, such as diallyl fumarate; PA1 lower alkyl esters of itaconic acid, such as dimethyl itaconate, diethyl itaconate, dipropyl itaconate and diisopropyl itaconate; and PA1 polycycloalkylene glycol monopropenyl ethers in which R.sup.5 is a cycloalkylene group, such as 1,2-cyclopentanediol monopropenyl ether, 1,2-cyclohexanediol monopropenyl ether and 1,2-cyclododecanediol monopropenyl ether. PA1 alkali metals, alkaline earth metals, oxides thereof and weak acid salts of these metals; PA1 oxides, hydroxides, alcoholates, organic acid salts (e.g., zinc acetate) and acetylacetonato complexes of Mn, Zn, Zr, Cd, Ti, Pb, Co and Sn; and PA1 dibutyltin oxide and dioctyltin oxide. PA1 wherein X represents --CH.dbd.CH-- or --CH.sub.2 --C(.dbd.CH.sub.2)--, each of R.sup.6 and R.sup.7, like R.sup.1 and R.sup.2 of the formula (1), independently represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n is an integer of 1 to 5, PA1 to thereby convert the allyl ether group "CH.sub.2.dbd.CH--CH.sub.2 --O--" to the propenyl ether group "CH.sub.3 --CH.dbd.CH--O--". PA1 wherein R.sup.8, like R.sup.6 and R.sup.7 of the formula (2), represents an alkylene group having 2 to 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms, and n, like n of the formula (2), is an integer of 1 to 5, provided that, when n=1, it is preferred that R.sup.8 represents an alkylene group having 3 or 4 carbon atoms or a cycloalkylene group having 5 to 12 carbon atoms. PA1 polyalkylene glycol monoallyl ethers in which R.sup.8 is an alkylene group, such as ethylene glycol monoallyl ether, propylene glycol monoallyl ether, 1,3-propanediol monoallyl ether, 1,4-butanediol monoallyl ether, 1,3-butanediol monoallyl ether, 1,2-octanediol monoallyl ether, diethylene glycol monoallyl ether, triethylene glycol monoallyl ether, tripropylene glycol monoallyl ether, tetraethylene glycol monoallyl ether and tetrapropylene glycol monoallyl ether; and PA1 wherein X represents --CH.dbd.CH-- or --CH.sub.2 --C(.dbd.CH.sub.2)-- and each of R.sup.3 and R.sup.4, as mentioned above, independently represents an alkenyl group or alkyl group having 1 to 3 carbon atoms, and PA1 the alcohol (alcohol (5)) represented by the above formula (5). PA1 lower alkyl esters of maleic acid, such as dimethyl maleate, diethyl maleate, dipropyl maleate, diisopropyl maleate and diallyl maleate; PA1 lower alkyl esters of fumaric acid, such as dimethyl fumarate, diethyl fumarate, dipropyl fumarate, diisopropyl fumarate and diallyl fumarate; and PA1 lower alkyl esters of itaconic acid, such as dimethyl itaconate, diethyl itaconate, dipropyl itaconate, diisopropyl itaconate and diallyl itaconate. With respect to the alkyl or alkenyl ester having 4 or more carbon atoms, the removal of by-products from the reaction system tends to be difficult because the boiling point of alkyl alcohol or alkenyl alcohol secondarily produced with the advance of the reaction is high. PA1 alkali metals, alkaline earth metals, oxides of these and weak acid salts thereof; PA1 oxides, hydroxides, alcoholates, organic acid salts and acetylacetonato complexes of Mn, Zn, Zr, Cd, Ti, Pb, Co and Sn; and PA1 dibutyltin oxide and dioctyltin oxide. PA1 ruthenium complexes such as dichlorotris(triphenylphosphine)ruthenium, dichlorotetrakis(triphenylphosphine)ruthenium, dihydridotetrakis(triphenylphosphine)ruthenium, chlorohydridotris(triphenylphosphine)ruthenium, carbonylchlorohydridotris(triphenylphosphine)ruthenium and carbonyldihydridotris(triphenylphosphine)ruthenium; and PA1 palladium complexes such as dichlorobis(benzonitrile)palladium, carbonyltris(triphenylphosphine)palladium, dichlorobis(trialkylphosphine)palladium, di-.mu.-chlorobis(.eta.-ethylene)dipalladium, di-.mu.-dichlorobis(triphenylphosphine)dipalladium, tetrakis(triphenylphosphine)palladium, dichloro(1,5-cyclooctadiene)palladium and dichloro(1,3-norbornadiene)palladium. These catalysts can be employed either individually or in combination. PA1 aromatic hydrocarbons such as benzene, toluene and xylene; PA1 ethers such as diethyl ether, dimethoxyethane, methoxyethyl ether and tetrahydrofuran; PA1 esters such as ethyl acetate, propyl acetate and butyl acetate; PA1 ketones such as acetone and methyl ethyl ketone; and PA1 alcohols such as methanol, ethanol, isopropyl alcohol and n-butyl alcohol. PA1 quinones such as p-benzoquinone and 2,5-diphenyl-p-benzoquinone; PA1 phenols such as hydroquinone, p-t-butylcatechol, 2,5-di-t-butylhydroquinone, mono-t-butylhydroquinone and tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionato]methane; and PA1 metal salts such as copper naphthenate and cobalt naphthenate. PA1 azo compounds such as 2,2'-azobisisobutyronitrile and 2,2'-azobisisovaleronitrile; PA1 ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide and cyclohexanone peroxide; PA1 diacyl peroxides such as benzoyl peroxide, decanoyl peroxide and lauroyl peroxide; PA1 dialkyl peroxides such as dicumyl peroxide, t-butyl cumyl peroxide and di-t-butyl peroxide; PA1 peroxyketals such as 1,1-di-t-butylperoxycyclohexane and 2,2-di(t-butylperoxy)butane; PA1 alkyl peresters such as t-butyl peroxypivalate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, di-t-butyl peroxyhexahydroterephthalate, di-t-butyl peroxyazelate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxyacetate, t-butyl peroxybenzoate and di-t-butyl peroxytrimethyladipate; and PA1 percarbonates such as diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate and t-butyl peroxyisopropylcarbonate. PA1 acetophenones and derivatives thereof, such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-l-(4-morpholinophenyl)-butanone-1 and 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzophenone and derivatives thereof, such as PA1 benzophenones, 4,4'-bis(dimethylamino)benzophenone, 4-trimethylsilylbenzophenone and 4-benzoyl-4'-methyldiphenyl sulfide; PA1 benzoins and derivatives thereof, such as benzoin, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether and benzoin isopropyl ether; and PA1 methylphenyl glyoxylate, benzoin dimethylketal and 2,4,6-trimethylbenzoyldiphenylphosphine oxide. These radical polymerization initiators can be employed either individually or in combination. PA1 coating materials for wood coating, film coating, metal coating, plastic coating, inorganic coating, hard coating and optical fiber coating; PA1 paint materials such as paints and printing inks; photoforming materials; optical materials such as optical disks, spectacle lenses and prisms; adhesives; photoresist; sealants; and molding compounds.
(4) Still further, Japanese Patent No. 2,744,849 describes a process for producing a polyester having vinyl ether terminals, which comprises the steps of:
Compounds of the formula Y-[COOX].sub.m (wherein Y: alkyl group, etc., X: alkyl having 1 to 6 carbon atoms, etc., and m is 2 to 6) in which Y may be --(CH.sub.2).sub.n -- are described as the above polybasic acid ester. The reaction of the formula: EQU XOCO--Y--COOX (i)+R'CH.dbd.CR"OZ-OH (ii).fwdarw. EQU R'CH.dbd.CR"OZ--OCO--Y--COO--ZOR"C.dbd.HCR'(iii)+2XOH.Arrow-up bold.
However, in the patent specification, there is no description regarding compounds wherein Y represents --CH.dbd.CH or --(CH.sub.2)--C(.dbd.CH.sub.2)--, and there is no description teaching or suggesting the radical polymerization of vinyl ether terminated ester (iii).
(5) Still further, claim 1 of Published Japanese Translation of PCT Patent Application No. 5(1993)-506838 describes an optical fiber coating composition comprising a product obtained by reacting together (a) a vinyl ether urethane oligomer composed of a product obtained by reacting together (i) a hydroxyl terminated polyester or hydroxyl terminated polyether, (ii) a diisocyanate or a polyisocyanate having at least two functional groups and (iii) a hydroxymonovinyl ether, (b) a vinyl ether terminated ester monomer and (c) a vinyl ether terminated monomer derived from a specified alcohol. A-(--COOZOCR.sub.4.dbd.CHR.sub.3).sub.n (wherein n: 1 to 4, A: alkylene group, etc., Z: alkylene, etc., each of R.sub.3 and R.sub.4 : H or alkyl group having 1 to 10 carbon atoms) is described as representing the above vinyl ether terminated ester monomer (b). In claim 3 thereof, --CH.dbd.CH--, etc. are listed as the above A, and --(CH.sub.2).sub.4 --O--(CH.sub.2).sub.4 --, --(CH.sub.2)4--O--(CH.sub.2).sub.4 --O--(CH.sub.2).sub.4 --, --CH.sub.2 CH.sub.2 --O--CH.sub.2 CH.sub.2 --, etc. are listed as the above Z. The specification also describes a composition comprising the above composition and a cationic polymerization initiator, etc.
However, although the specification describes an embodiment in which a cationic polymerization is performed with the use of a cationic photoinitiator of a triarylphosphonium hexafluorophosphate salt (Ar.sub.3 SPF.sub.6) (Union Carbide UVI-6960), there is no example performing the radical polymerization of the vinyl ether terminated ester monomer (b). As apparent therefrom, the specification neither describes any technical concept of effecting the radical polymerization of the above vinyl ether terminated ester monomer (b) nor suggests any technical concept of adding a radical polymerization initiator to the above composition containing the monomer (b) to thereby carry out the radical polymerization.